Rotterdam - Japan's Kei Nishikori insisted on Sunday he is back to '100 percent' as he returns to action after a right knee injury forced a painful exit at the Australian Open last month.
The 29-year-old is top seed in Rotterdam where he is looking for a second title of 2019 following a season-opening triumph in Brisbane.
World number seven Nishikori, who is no stranger to injury, saw his pursuit of a first Grand Slam title stall when he was forced to quit his Australian Open quarter-final at 6-4, 4-1 down to eventual champion Novak Djokovic in January.
"I am feeling well. It took maybe one week and a little bit to get 100 per cent, but now physically I am going well. I practiced well last week in Florida," said Nishikori on Sunday.
"It's going to be an interesting challenge this week. It's a strong tournament and many good players are playing, so it will be tough.
"I used to play (this week) in Memphis and last year in New York, but I like indoors and that's why I chose to come here."
The Asian number one starts his Rotterdam campaign against France's Pierre-Hugues Herbert who was runner-up to Jo-Wilfried Tsonga in Montpellier on Sunday.
Seeded second is last November's Paris Bercy champion Karen Khachanov of Russia with Greek breakthrough star Stefanos Tsitsipas, who beat Roger Federer on his way to the Australian Open semi-finals, taking the third seeding.
Number four seed is Canada's Milos Raonic, a quarter-finalist in Melbourne.
The field also features Canadian youngster Denis Shapovalov, with 2015 Rotterdam champion - and three-time major winner - Stan Wawrinka also in the draw.